General Motors has halted production of the top-of-the-line Chevy Camaro ZL1 over what the automaker is calling a "quality assessment" issue. What the hell does that mean?

The letter, obtained by GM Inside News, provides no date on resumption of production and shipment as well as no details on why. But here's the letter from GM to dealers:

03/02/2012

Ref. number:
Sales / New Vehicles / G_0000109294

Subject:
Update on 2012 Camaro ZL1 Shipments and DOSP

The purpose of this note is to provide you with an update on 2012 Camaro ZL1 production and vehicle shipment plans.

All Camaro ZL1 models produced to date are currently being held by General Motors for a quality assessment. At this moment, the duration of the hold is undetermined, and may last a few more weeks. As soon as the hold is cleared, a note will be sent to all dealers to advise that 2012 Camaro ZL1 shipments are underway.

Because of the hold, the upcoming Dealer Order Submission Process (DOSP) cycle that was to be dedicated to ZL1 is being postponed. This DOSP cycle was scheduled to start this Thursday, March 1, 2012, and continues through Tuesday, March 6, 2012. A new date for this DOSP cycle will be provided in the near future.

We regret to have to undertake these actions, especially given the high anticipation for the new Camaro ZL1. We ask for your patience and will continue to keep you posted on any developments regarding production and vehicle shipments from Oshawa.